There's a fine line between being tough and taking an unnecessary risk. If you're not in a position where you can walk into your job to find it doesn't exist anymore, it is your obligation to yourself and your family to manage that. If you can take the risks to stay, why couldn't you also take the risks to change jobs often?

If you're looking only for people who can put themselves in that position, then I'd bet you'd find a good number of them to be job-hoppers.